The swearing-in ceremony for legislators is supposed to be a solemn event marked by tradition.

But strategic coughing, shouted slogans and a call for "comrades" to strive for a successful revolution punctuated a day packed with rhetoric and gimmicks yesterday.

Three lawmakers from the radical pan-democratic People Power group took turns showing their flair for the dramatic with their own versions of the legislator's oath of office.

On a day that was also the anniversary of the 1911 revolution, Albert Chan Wai-yip carried a portrait of Dr Sun Yat-sen, known as the father of modern China, in with him.

Before and after he took his oath, he chanted slogans calling for power to the people. Chan read the oath in a loud voice, but deliberately lowered his voice for the word "republic" when pledging allegiance to the "Hong Kong Special Administrative Region of the People's Republic of China".

Wong Yuk-man, who represents Kowloon West, coughed when he read some key words of the oath.

"I swear that, being a member of the Legislative Council of Hong Kong [cough], of the People [cough] of China, I will uphold the Basic Law of Hong Kong [cough], of the People [cough] of China," he said.

Then he shouted slogans: "Long live the people, long live democracy, down with the Hong Kong communist regime; down with [Chief Executive] Leung Chun-ying."

Raymond Chan Chi-chuen, the first openly gay politician in Hong Kong, repeated Sun's dying instruction, "The revolution has not yet succeeded, comrades still need to work harder", before he took his oath. "Comrade", or tongzi in Cantonese, can also be used to refer to homosexuals.

"Long Hair" Leung Kwok-hung, of the League of Social Democrats, started by shouting: "I want genuine universal suffrage; I don't want Article 23 [national security legislation]." He also shouted slogans afterwards.

Gary Fan Kwok-wai, of the NeoDemocrats, added his platform of defending Hong Kong's core values after the oath.

Under Legco's rules of procedure, a lawmaker cannot attend a meeting until he has made his oath or affirmation.

Under the law, a lawmaker could lose his seat if he declines or neglects to take an oath.

After the meeting, Wong insisted he completed the oath.

"Of course I finished it," he said. "Sometimes you will cough while you are reading … I have already pledged my allegiance to the people. "

Jasper Tsang Yok-sing, who was re-elected as Legco president yesterday, said a legal adviser would study the matter carefully.

Tsang said: "According to our law, lawmakers must read out the entire oath of office." But he acknowledged that "for whatever reason" the oaths of some lawmakers might be unclear.

University of Hong Kong assistant law professor Eric Cheung Tat-ming said Wong could be asked to take the oath again.

This article appeared in the South China Morning Post print edition as Little solemnity as Legco splutters into action